Solar Guppy - All Things Solar Forum

It is currently Wed Oct 28, 2020 5:04 pm GMT EthGMT

All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 50 posts ]  Go to page 1, 2, 3, 4  Next
Author Message
 Post subject: Upgrading System, need some advice.
PostPosted: Thu Dec 13, 2007 12:54 pm GMT EthGMT 
Offline
Guppy
Guppy

Joined: Thu Dec 06, 2007 11:34 am GMT EthGMT
Posts: 105
Location: Maine
First I wanted to ask a couple questions about the MX60 and GVFX3524. I saw that MX60 sometimes had problems with Radio Interferance. We currently have a Trace C40 and DR3624 inverter and we had to move phone wires and computer networking cable away from it after installation due to interferance. We no longer have problems, but my father runs a Ranger 2995DX Ham Radio in the same household about 25 ft away and the wiring never gets any closer than 25ft. If we were to upgrade to an Outback system, would that be too close? Or would EMI be about the same? :?:

Next I wanted ask about MX60 Wiring. By my understanding of the MX60's limitations, if you have a rated VOC 0f 47.7volts and weather that could drop as low as -20 Degrees Fahrenheit. It would not be wise Use series strings of 3 as the VOC could reach 143.1 volts, which exceeds the charge current of the MX60. In reality though, how often would it reach that voltage if it were -20 degrees, with a clear sky and fresh snow?
I was going to wire the panels I have at 80volts (95.4 VOC) in series strings of 2. I have 14 of these Sunpower SPR-215-BLK panels, and yes Im aware they are positive ground. From what I understand they still work, they just might be up to 30% less efficient than they could be.Anyway this gives me 7 Strings at 95.4 VOC & 5.9Amps Short Circuit Current. I am planning on wiring the first 4 strings at 2 strings each to 2 MX60 charge controllers at 860 watts max per MX60 and the last 3 Strings to 1 MX60 at 1290 Watts max. The arrays are 150ft away with 3 seperate runs of 4 Gauge Aluminum Wire. :? :idea:

Does anyone see anything wrong with this setup of have anything that they would like to point out? Is there a more efficient way to do this without upgrading the battery bank to 48volts? (They need to be 24volts for other charging devices.) This will be a grid tied setup by the way and we have now 16 6volt 400ah batteries from US Battery. Also, is there any reason I should seriously consider the new XW4024 system from Xantrex? :?: :idea:


Top
 Profile  
 
 Post subject: Re: Upgrading System, need some advice.
PostPosted: Thu Dec 13, 2007 1:44 pm GMT EthGMT 
Offline
Guppy
Guppy
User avatar

Joined: Fri Aug 04, 2006 10:24 am GMT EthGMT
Posts: 284
Location: Los Angeles
Iboc wrote:
is there any reason I should seriously consider the new XW4024 system from Xantrex? :?: :idea:


How long can you hold your breath ?

Series strings are better for less copper loss.

_________________
"Since the dawn of time it has been mankind's dream to blot out the sun"
Montgomery Burns


Top
 Profile  
 
 Post subject:
PostPosted: Thu Dec 13, 2007 1:52 pm GMT EthGMT 
Offline
Guppy
Guppy

Joined: Thu Dec 06, 2007 11:34 am GMT EthGMT
Posts: 105
Location: Maine
I would have used copper for the wire runs as we did on our original array 10 years ago, but it is overpriced due to china's high copper consumption. Only aluminum was available in 4 gauge wire. They had 4 guage aluminum and 8 guage copper for the same price. But 8 guage wasn't going to do it at 150ft. Also it was direct burial capable wire but we burried it inside 2.5 inch conduit FYI.


Top
 Profile  
 
 Post subject:
PostPosted: Thu Dec 13, 2007 4:31 pm GMT EthGMT 
Offline
Guppy
Guppy
User avatar

Joined: Mon Mar 20, 2006 7:58 pm GMT EthGMT
Posts: 214
Location: pittsburgh
what mike meant was that you will lose less power through your wires when higher voltages are used. aluminum wire cannot handle as much power for the same gauge # as copper can handle. aluminum has a higher resistance is the reason why. also note that when copper and aluminum mix, as in your connection points, that it sets up what they call galvanic reactions so you need to be sure that the controller you get can accomodate the aluminum wire or you will have to make an adaptive provision approved for that purpose. fires have occured during the 60s and 70s because of aluminum wire used on copper only connections. on this point maybe solar guppy can add to my post by saying of the xw60's possible compatibility with aluminum wires.
as to reducing the rfi/emi, the xw is obviously better for it. keep in mind that interference is a 2 way street as the radio may interfere with the controller's operations too. any that is proven to be in compliance on outgoing interference will also reject interference getting into the controller to that same degree. you may or may not have a problem with using the mx60 with that radio, but for about the same money why not get the xw60? i don't mean to scare you, but even with an approved controller for interference there are no guarantees of being interference free as that approval only indicates that it is sufficiently reduced in strength, but look at what it might be otherwise without that reduction.
you may have read the thread on the interference, but these steps and measures do apply to nearly all items emitting or receiving interference. http://www.solar-guppy.com/forum/viewtopic.php?t=568 you may not be familiar with these steps and may not have to be in most cases.


Last edited by niel on Thu Dec 13, 2007 10:33 pm GMT EthGMT, edited 1 time in total.

Top
 Profile  
 
 Post subject:
PostPosted: Thu Dec 13, 2007 5:41 pm GMT EthGMT 
Offline
Guppy
Guppy

Joined: Thu Dec 06, 2007 11:34 am GMT EthGMT
Posts: 105
Location: Maine
Ok, so if I understand you correctly, the MX60 is rated for copper wire not aluminum? Arggg. I never noticed that in the users manual. Ok, well I can make accomodations for that, Im sure someone at the Electrical Engineering firm that I work at would be familiar converting aluminum wire to copper, being that all our ground wires for High Voltage transmission lines (115,000 kV+ 3 Phase AC) use aluminum static wire and are bonded to copper ground wires on each pole. :roll:

Also, there are 2 reasons I would go with the MX60 over the XW. For one if I buy the GVFX3524, I want to be able to network them and control them with the hub. Second is price, on most sites the XW is $100 more. I will need 4 MPPT controllers for 3.7kw because we are using 24volts. I don't want to dish out the $400 additional that it would take to have the latest and greatest when the MX60 could be had for less and will probably perform the same task. -Also, on that note, the average income in our area is only $33,000 per year. Even though we are living slightly above that average, the rest of the country lives MUCH farther above that average. If I did the same job I do now in but in MASS, I would get paid 4 to 5 times what I get here. Even in southern maine, our competition pays double in Portland what I get here in Augusta, and this is the state capitol. Basically this is being scraped together for as little money as possible because we are also putting in a Skystream 3.7 WindTurbine and Repairing our 85 yr old chimney. Need to save every penny we can, but I will refuse to do anything unsafe, even if it takes us a couple months extra to finnish assembly due to money issues. Thanks for everyone's input so far, gets me thinking about issues I haven't thought about yet.


Top
 Profile  
 
 Post subject:
PostPosted: Thu Dec 13, 2007 7:52 pm GMT EthGMT 
Offline
Minnow
Minnow

Joined: Tue Sep 25, 2007 5:04 pm GMT EthGMT
Posts: 14
Location: Vista, CA
Remember to use an approved anti-oxidant compound when making connections to aluminum wire.


Top
 Profile  
 
 Post subject:
PostPosted: Thu Dec 13, 2007 10:41 pm GMT EthGMT 
Offline
Guppy
Guppy
User avatar

Joined: Mon Mar 20, 2006 7:58 pm GMT EthGMT
Posts: 214
Location: pittsburgh
if you are set with the mx60 then i might suggest you to go onto the outback forum and ask them if the connectiions inside are capable of an aluminum wire. you may find what you need on it before posting, but it is large so you may not find it even if it is there. register and ask.
http://www.outbackpower.com/forum/


Top
 Profile  
 
 Post subject:
PostPosted: Fri Dec 14, 2007 9:40 am GMT EthGMT 
Offline
Guppy
Guppy

Joined: Thu Dec 06, 2007 11:34 am GMT EthGMT
Posts: 105
Location: Maine
Thanks for the pointer. I have heard alot of good things about the Outback equipment. But the Xantrex equipment is so new, I dont know if I want to be a Guinea Pig for the latest, greatest, most untested, most unproven tech. Especially when it costs more.... It is tempting though.


Top
 Profile  
 
 Post subject:
PostPosted: Fri Dec 14, 2007 3:31 pm GMT EthGMT 
Offline
Guppy
Guppy

Joined: Thu Dec 06, 2007 11:34 am GMT EthGMT
Posts: 105
Location: Maine
Ok Guys, I checked in on the aluminum wire, I "Should" use a terminal block for the adaptation. Now I have a couple more questions.

1.) Is there anyone in particular that I should contact to come an inspect this system once its installed? We are the only people in our town with PVs or Wind Turbines. The town says we dont need construction permits, they also dont have any permits or wind turbines or solar and no electrical inspectors. Central Maine Power also does not Inspect home pv systems. I was told that for a NetMetering contract, just call them and tell them what kind of invertor so they know if it shuts down automatically when the grid goes out. They said they dont have time to inspect them, they will just take us at our word. So aside from the town and the Utility, is there anyone else that would want to inspect this system?

2.) There is a 70' Retractable Ham Radio antenna right next to the arrays (30ft +or-) made of laticework steel no wider than 1.5". At 30ft, and 1.5" wide. Will the steel affect the summer morning output of the arrays greatly? It's Directly East of the Array Position.


Top
 Profile  
 
 Post subject:
PostPosted: Fri Dec 14, 2007 5:08 pm GMT EthGMT 
Offline
Guppy
Guppy
User avatar

Joined: Wed Apr 19, 2006 1:02 am GMT EthGMT
Posts: 110
Location: SF Bay Area
Sounds like you have checked with all of the proper people regarding permits/inspections (nobody does electrical/building permits/inspections for just normal home building/remodels?--cool. In my city in California, the old planning commission was just as bad as a city-wide homeowners association)... The last one you may check with is your insurance agent/company if they have any issues (do they require you to use a licensed electrician--for example).

Any shading will cut your solar power output dramatically (in my humble opinion, if you have 2 or more parallel strings, shading even a few cells in a panel runs the risk of dropping close to 100% of the power from the one string).

On the other hand, if these are fixed panels (not tracking), you probably don't generate much power when the sun is due east. It would be better to avoid the shadows of fixed structures (and even power lines) whenever you can--because these are (many times) preventable losses that will add up over 20-30 years of generation. If you have no choice--there is not much you can probably do other than to accept the losses.

-Bill


Top
 Profile  
 
 Post subject:
PostPosted: Fri Dec 14, 2007 9:29 pm GMT EthGMT 
Offline
Red Cobra Delta Guppy
Red Cobra Delta Guppy
User avatar

Joined: Sun Jun 02, 2002 1:01 am GMT EndGMT
Posts: 1158
Location: Lakeland Florida
You will have shading in the summer months if its east of the array as at your lattitude you will have ~220 degrees of rotation in June, from a chart from

http://solardat.uoregon.edu/SunChartProgram.html

I used bangor's zip code and you will be shaded before 8am which looks like 3.5 hours of daylight ( man the sunrises early there in the summer! )

You will probably have excess power in the summer, so I wouldn't be to concerned


Top
 Profile  
 
 Post subject:
PostPosted: Sat Dec 15, 2007 7:46 pm GMT EthGMT 
Offline
Guppy
Guppy
User avatar

Joined: Mon Mar 20, 2006 7:58 pm GMT EthGMT
Posts: 214
Location: pittsburgh
Iboc wrote:
Ok Guys, I checked in on the aluminum wire, I "Should" use a terminal block for the adaptation. Now I have a couple more questions.

1.) Is there anyone in particular that I should contact to come an inspect this system once its installed? We are the only people in our town with PVs or Wind Turbines. The town says we dont need construction permits, they also dont have any permits or wind turbines or solar and no electrical inspectors. Central Maine Power also does not Inspect home pv systems. I was told that for a NetMetering contract, just call them and tell them what kind of invertor so they know if it shuts down automatically when the grid goes out. They said they dont have time to inspect them, they will just take us at our word. So aside from the town and the Utility, is there anyone else that would want to inspect this system?

2.) There is a 70' Retractable Ham Radio antenna right next to the arrays (30ft +or-) made of laticework steel no wider than 1.5". At 30ft, and 1.5" wide. Will the steel affect the summer morning output of the arrays greatly? It's Directly East of the Array Position.


good to find out about the requiremnt of the terminal block for adaptation as i didn't know if it needed it or not and now i know too.
if you are confident that you can do the electrical work you can just follow the nec rules or get an electrician to either do the work for you or have one advise and inspect your work. do note that there would not be anybody to force the nec rules upon you unless required by your home owners insurance and they would most likely force that upon you. if you don't follow the nec guidelines they may say you made it unsafe by not following the nec and they may refuse to pay for any damages with an out for them like that. insurance companies can be royal pains in the *ss and will look for any excuse to not pay for the protection you are paying them for and do know the nec is sometimes hard to interpret.
as to xantrex being new, they are not new and i believe the company is older than outback, sg correct me if i'm wrong. now, i understand what you meant though with particular products being new to the market as newer items tend to need bugs worked out of them in the beginning.
as to the shade, yes, you will have a slight degradation between the beginning of spring and the end of summer for less than an hour of morning sun, but it won't amount to much lost power imho.


Top
 Profile  
 
 Post subject:
PostPosted: Sun Dec 16, 2007 9:41 am GMT EthGMT 
Offline
Guppy
Guppy

Joined: Thu Dec 06, 2007 11:34 am GMT EthGMT
Posts: 105
Location: Maine
Thanks everyone. I didn't think think that the tower would be a big problem. We are situated in a valley with an amazing view of the southern sky (good for satallite), but due to this arrangment, what should be the first and last 1.5 hours of the day in the summer are actually blocked by the hills on either side. In the winter its only obstructed for about 1/2 an hour. The tower is not an issue in the winter. My father an I re-wired this whole house our self, we have never used licenced electricians. The insuance compant (State Farm) has never given us any greef over anything, as a matter of fact, we got the home equity loan that is paying for the solar and windmill from them! The windmill is being installed professionally though, a rebar reinforcing cage filled with concrete for a Caisson and a 50' tower is a little bit more than I'm willing to deal with on my own without a construction team. I will be sure to get pointers from their electrician.
:arrow: As for Xantrex. I was only worried about thier NEW equipment. We have used a Trace (Xantrex) Power Panel and DR3624 for about 9 years. The DR always worked as intended for backup power, but a squar sign wave is a pain in the ass! And you can't possibly grid tie it. We have also used C-40 charge controllers for just as long.


Top
 Profile  
 
 Post subject:
PostPosted: Sun Dec 16, 2007 12:17 pm GMT EthGMT 
Offline
Red Cobra Delta Guppy
Red Cobra Delta Guppy
User avatar

Joined: Sun Jun 02, 2002 1:01 am GMT EndGMT
Posts: 1158
Location: Lakeland Florida
The XW is far from "new" ... When I was working on the SC-60, the Inverter project had been going for a full year, so its over 4 years old now and a very elegant and great performing inverter, nothing on the market comes close it its peformance and efficiency. You get true 240 split phase, 12kw surge and 95% efficiency all in one box.

I know whats inside most of the solar hardware sold and how it all works, if it means anything hearing it from me, you shouldn't have any concerns selecting XW stuff.


Top
 Profile  
 
 Post subject:
PostPosted: Mon Dec 17, 2007 5:52 pm GMT EthGMT 
Offline
Guppy
Guppy
User avatar

Joined: Mon Mar 20, 2006 7:58 pm GMT EthGMT
Posts: 214
Location: pittsburgh
sg,
do you know if the xw would accomodate aluminum wires or will it too need adapted?


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 50 posts ]  Go to page 1, 2, 3, 4  Next

All times are UTC - 5 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
cron
Powered by phpBB © 2000 - 2020 phpBB Group

phpBB SEO

© SGT 2002 - 2020 Solar Guppy